New analytical method for determination of epimer metabolites in rat plasma after oral administration of Paeoniflorin by UPLC-TOF-MS following picolinoyl derivatization

A highly sensitive analytical method was developed to study the in vivo metabolism of paeoniflorin, one of the most principal components in traditional Chinese medicine. After hydrolyzation with sulfatase, the epimer metabolites 7S-paeonimetabolin I and 7R-paeonimetabolin I of paeoniflorin in rat plasma were successfully detected and well separated by LC–MS following picolinoyl derivatization for the first time. Borneol was used as the internal...